Look what I dug up

[Diggerette]

I do believe these are old.....
The broken one is a Federal Monarch and the other says U.M.C.Co. New Club 12 ga.

 

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[Critical Recovery]

Those are the bases to shotgun shells.

The remainder of the shell was constructed of paper, and the paper rots away, leaving the brass base.
The are from around 1900-1960 (roughly) when they switched from paper hulls to plastic.